ABC is taking a less conventional approach with an upcoming series based on the comedy/drama procedural Castle, following fictional author Richard Castle (Nathan Fillion) and NYPD detective Kate Beckett (Stana Katic).

Variety reports ABC is in the early stages of developing a new show based on the ‘Derrick Storm’ books; though the project isn’t technically considered a spinoff, the Storm character was originally created as a fictional series written by Fillion’s character on Castle. Gregory Poirier (Missing) will write the pilot script and executive produce the show along with Castle’s creator Andrew Marlowe and executive producer Terri Edda Miller.

Although Derrick Storm started off as a fictional character written by the fictional author Richard Castle, a series of actual books — and graphic novel adaptations — were published under the penname. The mystery series follows Storm, a spy recruited by the CIA for missions, and has become a bestseller.

With Castle about to enter its seventh season and the ratings continuing to improve, it’s no wonder why ABC would want to develop a spinoff series — even if the show isn’t necessarily envisioned as a spinoff. In season 6 of Castle, the show saw some of its highest ratings yet, which provides a solid audience base for any series related to the procedural drama.

Of course, as seen with other spinoffs, this doesn’t necessarily guarantee success for a Storm series. While the procedural format would be easy to translate to a spy drama, Castle’s success may stem more from its leads, Fillion and Katic, than the show’s weekly murder cases.

However, since Castle’s fans have turned the actual Derrick Storm novels into best-sellers, it may be safe to think they’d tune in for a television series based on the character. Whether they’ll stick around is another story.

Stay tuned to Screen Rant for more on the developing Derrick Storm series; Castle returns on Monday September 29th @10PM on ABC.